From patchwork Mon Jan 20 15:01:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oscar A Perez X-Patchwork-Id: 1226200 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 481rFC0W74z9sR0 for ; Tue, 21 Jan 2020 12:15:27 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=neuralgames.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=neuralgames.com header.i=@neuralgames.com header.a=rsa-sha256 header.s=default header.b=kY+GPOBB; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 481rFB1fJRzDqfN for ; Tue, 21 Jan 2020 12:15:26 +1100 (AEDT) X-Original-To: linux-aspeed@lists.ozlabs.org Delivered-To: linux-aspeed@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=neuralgames.com (client-ip=69.13.37.146; helo=kross2019.rwserver.com; envelope-from=linux@neuralgames.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=neuralgames.com Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=neuralgames.com header.i=@neuralgames.com header.a=rsa-sha256 header.s=default header.b=kY+GPOBB; dkim-atps=neutral Received: from kross2019.rwserver.com (kross.rwserver.com [69.13.37.146]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 481Zrk1V3JzDqSD for ; Tue, 21 Jan 2020 02:11:48 +1100 (AEDT) Received: from localhost (localhost [127.0.0.1]) by kross2019.rwserver.com (Postfix) with ESMTP id 3E1EBB3629; Mon, 20 Jan 2020 09:01:33 -0600 (CST) Authentication-Results: kross2019.rwserver.com (amavisd-new); dkim=pass (1024-bit key) reason="pass (just generated, assumed good)" header.d=neuralgames.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=neuralgames.com; h=x-mailer:message-id:date:date:subject:subject:from:from; s= default; t=1579532490; x=1581346891; bh=dshgkKumJVS0zAqIIrcV+cw7 enEW8iyIBXeKU3OU9w4=; b=kY+GPOBBbjAO2SEjaQm70ehoBqYzhl9zuqJcDvf9 rZjYn0c8QmwPVNoZ13ejhQEWEEnhy4Kh5ot8OLH+v4A4uxbzILR/GUZ+2SXAfMJp Ie2Jt9n13YD3PsTv8s1wVAI0BzbzOf1+onms+kCrTQTe3ti050chJ2HoYxhOJn6F Yyg= X-Virus-Scanned: Debian amavisd-new at kross2019.rwserver.com Received: from kross2019.rwserver.com ([127.0.0.1]) by localhost (kross2019.rwserver.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 5l7g2zoo_9du; Mon, 20 Jan 2020 09:01:30 -0600 (CST) Received: from localhost (ZT-GROUP-IN.bear1.Houston1.Level3.net [4.14.58.158]) (Authenticated sender: linux@neuralgames.com) by kross2019.rwserver.com (Postfix) with ESMTPSA id 9F147B3628; Mon, 20 Jan 2020 09:01:30 -0600 (CST) From: Oscar A Perez To: Matt Mackall , Herbert Xu , Rob Herring , Mark Rutland , Joel Stanley , Andrew Jeffery , Oscar A Perez , linux-crypto@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] hwrng: Add support for ASPEED RNG Date: Mon, 20 Jan 2020 15:01:08 +0000 Message-Id: <20200120150113.2565-1-linux@neuralgames.com> X-Mailer: git-send-email 2.17.1 X-Mailman-Approved-At: Tue, 21 Jan 2020 12:15:20 +1100 X-BeenThere: linux-aspeed@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux ASPEED SoC development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-aspeed-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linux-aspeed" This minimal driver adds support for the Hardware Random Number Generator that comes with the AST2400/AST2500/AST2600 SOCs from AspeedTech. The HRNG on these SOCs uses Ring Oscillators working together to generate a stream of random bits that can be read by the platform via a 32bit data register. Signed-off-by: Oscar A Perez --- .../devicetree/bindings/rng/aspeed-rng.yaml | 90 +++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 Documentation/devicetree/bindings/rng/aspeed-rng.yaml diff --git a/Documentation/devicetree/bindings/rng/aspeed-rng.yaml b/Documentation/devicetree/bindings/rng/aspeed-rng.yaml new file mode 100644 index 000000000000..06070ebe1c33 --- /dev/null +++ b/Documentation/devicetree/bindings/rng/aspeed-rng.yaml @@ -0,0 +1,90 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: "http://devicetree.org/schemas/rng/aspeed-rng.yaml#" +$schema: "http://devicetree.org/meta-schemas/core.yaml#" + + +title: Bindings for Aspeed Hardware Random Number Generator + + +maintainers: + - Oscar A Perez + + +description: | + The HRNG on the AST2400/AST2500/AST2600 SOCs from AspeedTech uses four Ring + Oscillators working together to generate a stream of random bits that can be + read by the platform via a 32bit data register every one microsecond. + All the platform has to do is to provide to the driver the 'quality' entropy + value, the 'mode' in which the combining ROs will generate the stream of + random bits and, the 'period' value that is used as a wait-time between reads + from the 32bit data register. + + +properties: + compatible: + oneOf: + - items: + - enum: + - aspeed,ast2400-rng + - aspeed,ast2500-rng + - aspeed,ast2600-rng + + + reg: + description: + Base address and length of the register set of this block. + Currently 'reg' must be eight bytes wide and 32-bit aligned. + + maxItems: 1 + + + period: + description: + Wait time in microseconds to be used between reads. + The RNG on these Aspeed SOCs generates 32bit of random data + every one microsecond. Choose between 1 and n microseconds. + + maxItems: 1 + + + mode: + description: + One of the eight modes in which the four internal ROs (Ring + Oscillators) are combined to generate a stream of random + bits. The default mode is seven which is the default method + of combining RO random bits on these Aspeed SOCs. + + maxItems: 1 + + + quality: + description: + Estimated number of bits of entropy per 1024 bits read from + the RNG. Note that the default quality is zero which stops + this HRNG from automatically filling the kernel's entropy + pool with data. + + maxItems: 1 + + +required: + - compatible + - reg + - period + - quality + + +examples: + - | + rng: hwrng@1e6e2074 { + compatible = "aspeed,ast2500-rng"; + reg = <0x1e6e2074 0x8>; + period = <4>; + quality = <128>; + mode = <0x7>; + }; + + +...